Drug & supplement interaction

Ostrich Fern + Pretomanid

Pretomanid brand name: Pretomanid.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 27, 2026
The bottom line No known interaction

We found no known interaction between Ostrich Fern and Pretomanid in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Pretomanid states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Ostrich Fern and Pretomanid

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Pretomanid and Ostrich Fern in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Ostrich Fern at all — not against Pretomanid, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Ostrich Fern safety at a glance

Ostrich Fern overall Use caution Generally treated as a food, but raw or undercooked fiddleheads can cause foodborne illness.
Pregnancy Avoid Not enough safety information; avoid medicinal use and never eat them raw or undercooked.
Breastfeeding Use caution Little safety data; well-cooked fiddleheads eaten as food are likely fine, but avoid concentrated or medicinal use.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Pretomanid and Ostrich Fern? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Ostrich Fern and Pretomanid May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Stomach pain / Nausea / Diarrhea / Vomiting / Headache reported in 6.2% of FDA reports for Pretomanid Additional detail

    Ostrich Fern

    “Orally, no adverse effects have been reported when ostrich fern is used medicinally. However, a thorough evaluation of safety outcomes has not been conducted. Eating the young shoots of ostrich fern without proper cooking can cause nausea, vomiting, abdominal cramping (6), diarrhea, and headaches.”

    Ostrich Fern · Natural Medicines adverse-effect record, reported in diarrhea.

    2 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 5002. Centers for Disease Control and Prev. Ostrich fern poisoning New York and western Canada, 1994. JAMA 1995;273:912-3.

    “When consumed as food, the young shoots of ostrich fern (fiddleheads) must be cooked thoroughly (e.g., boiling for 10 minutes) before eating. The Centers for Disease Control and Prevention (CDC) links outbreaks of severe food poisoning to consumption of raw or lightly cooked ostrich ferns (6,5002). Ostrich fern can cause nausea, vomiting, abdominal cramping (6), diarrhea, and headaches after ingestion.”

    Ostrich Fern · Natural Medicines adverse-effect record, reported in diarrhea.

    2 sources cited
    1. 5002. Centers for Disease Control and Prev. Ostrich fern poisoning New York and western Canada, 1994. JAMA 1995;273:912-3.
    2. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.

    Pretomanid

    Listed in the ADVERSE REACTIONS section of the FDA label for Pretomanid, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Effects for Pretomanid come from the ADVERSE REACTIONS section of its FDA label; effects for Ostrich Fern come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 647 voluntary FDA FAERS reports for Pretomanid that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Pretomanid Products Have a Food Rule — Ostrich Fern Should Not Break It

At least one FDA label for a product containing Pretomanid says to take it with food. If you take Ostrich Fern on an empty stomach out of habit, keep them separate — and take Pretomanid with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Pretomanid products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Recommended Dosage Pretomanid Tablets must be administered in combination with bedaquiline and linezolid with food [see Clinical Pharmacology (12.3) ] .

From the Dosage and Administration section of the FDA label we read for Pretomanid — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Pretomanid

This page covers Ostrich Fern only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pretomanid page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 10 major · 122 moderate · 11 minor.

From our pharmacist’s overview on the Pretomanid page

“Pretomanid is reserved for highly drug-resistant tuberculosis, and it can stress the liver and lengthen the heart's QT interval, so the supplements on this page deserve genuine care. Ten of the 143 ingredients on file carry a major rating, and nearly all of those either compound the liver risk (alcohol in beer or wine is the plainest e…”

Reviewed by 2 · Jul 18, 2026

Open the Pretomanid interaction page

How much people look this up

Where Ostrich Fern and Pretomanid Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Ostrich Fern
Steady interest

#1,427 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Pretomanid
Steady interest

#1,499 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Ostrich Fern reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Ostrich Fern and Pretomanid records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Ostrich Fern

What is Ostrich Fern?

  • Seasonal food/vegetable
  • Source of vitamins and antioxidants
  • Traditional spring tonic
  • Digestive support (traditional)

Ostrich fern is best known as a foraged spring vegetable called a fiddlehead, not as a medicinal supplement. There is very little scientific evidence supporting any health benefit, and raw or undercooked fiddleheads can cause food poisoning, so they must always be thoroughly cooked.

Matteuccia struthiopteris · Onocleaceae · Young curled shoots (fiddleheads) · Fresh or frozen fiddleheads (cooked as a vegetable); rarely as a foraged food

An interaction check asks whether these two react with each other — it does not ask whether Ostrich Fern is a good idea for someone in your situation. Here is what our Ostrich Fern record says about it on its own.

Ostrich Fern: dosing

There is no established medicinal dose for ostrich fern, and it is not sold as a standardized supplement. When preparing fiddleheads at home, focus on thorough cooking rather than any particular "dose."

From our Ostrich Fern monograph — the full record covers uses, side effects and every documented interaction.

Read the full Ostrich Fern monograph & all interactions
Medication

About Pretomanid

What Is Pretomanid Used For?

Brand name: Pretomanid

Pretomanid Tablet is used only as part of a three-drug regimen — together with bedaquiline and linezolid — to treat adults with pulmonary (lung) tuberculosis that is resistant to multiple antibiotics, including isoniazid, rifamycins, a fluoroquinolone, and a second-line injectable TB drug. It is also used for adults whose TB is resistant to isoniazid and rifampin and who cannot tolerate or are not responding to standard TB therapy.

Pretomanid Tablets are not for drug-sensitive TB, latent (inactive) TB infection, TB outside the lungs, or TB that responds to standard treatment. They should only be used in combination with bedaquiline and linezolid — safety and effectiveness with other drug combinations have not been established.

See full Pretomanid drug information
Keep checking

Other Drugs & Ostrich Fern

Browse every other medication we’ve checked against Ostrich Fern — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

We also checked Ostrich Fern against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Ostrich Fern list.

See the full Ostrich Fern interactions page
See every supplement checked against Pretomanid, ranked by severity
Evidence & sources

Ostrich Fern References

The 2 references that drive our Ostrich Fern monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Centers for Disease Control and Prev. Ostrich fern poisoning New York and western Canada, 1994. JAMA 1995;273:912-3.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Ostrich Fern and Pretomanid Together: Common Questions

Is it safe to take Ostrich Fern with Pretomanid?
We do not list a known interaction between Ostrich Fern and Pretomanid. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Ostrich Fern and Pretomanid have any of the same side effects?
Yes — our sources link each of them separately to 5 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Ostrich Fern and Pretomanid at the same time of day?
At least one FDA label for a product containing Pretomanid says to take it with food. If you take Ostrich Fern on an empty stomach out of habit, keep them separate and take Pretomanid with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Pretomanid products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Pretomanid interact with any supplements?
Yes. Pretomanid has documented interactions with 143 supplements in our database — Ostrich Fern is not one of them. The Pretomanid interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Ostrich Fern monograph Uses, safety profile, and every drug interaction in one place Pretomanid drug information The full plain-English guide to this medication Pretomanid supplement interactions Every supplement checked against Pretomanid, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Pretomanid and Ostrich Fern?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.